Upper Arm Anatomy

Upper Arm Structure

• The upper arm extends from the shoulder to the elbow.
• It is divided into two compartments: anterior and posterior, by the medial and lateral intermuscular septa.

Anterior Compartment

• Contains muscles that flex the elbow joint.
• Muscles in this compartment include:
  • Biceps brachii
  • Brachialis
  • Coracobrachialis
• Blood vessels: Brachial A., Brachial V.
• Nerve supply: Musculocutaneous N.

Muscles in Anterior Compartment

• Biceps brachii: has two heads and two sites of insertion.
• Coracobrachialis: originates from the coracoid process and inserts into the medial side of the humerus.
• Brachialis: originates from the anterior surface of the humerus and inserts into the ulnar tuberosity.
• Nerve supply: Musculocutaneous N.
• Action: elbow flexion, shoulder flexion (Coracobrachialis & Long head of biceps).

Brachial Artery

• Begins as a continuation of the axillary artery at the lower border of the teres major muscle.
• Terminates just distal to the elbow joint, dividing into the radial and ulnar arteries.
• It is palpable along its length.
• In proximal regions, the brachial artery can be compressed against the medial side of the humerus.
• Branches:
  • Muscular
  • Profunda brachii
  • Humeral nutrient
  • Sup. Ulnar collateral
  • Inf. Ulnar collateral
  • Terminal: Radial and Ulnar

Veins in the Arm

• There are two sets of veins in the arm: superficial and deep.
• Superficial veins:
  • Basilic V.: originates at the distal part of the arm, runs medially, then penetrates deep fascia to become medial to the brachial A., and finally becomes the axillary V. at the lower border of the teres major muscle.
  • Cephalic V.: passes superiorly on the anterolateral aspect of the arm, and through the anterior wall of the axilla to reach the axillary vein.

This quiz covers the anatomy of the upper arm, including its compartments, muscles, blood vessels, and nerve supply. Learn about the anterior and posterior compartments, the muscles that flex and extend the elbow joint, and more.